1. Field
The present disclosure relates to helmets. More particularly, the present disclosure relates to protective helmets having enhanced protective performance characteristics. The present disclosure has application to football helmets, ice-hockey helmets, baseball helmets, motorcycle helmets, riot helmets, military helmets and other similar helmets, although it is not limited thereto.
2. State of the Art
Head trauma resulting from sports and other activities is a common occurrence. Generally, head trauma occurs when an object impacts the head, thereby transferring energy to the head. The most common head trauma resulting from sports is a concussion, which occurs when the brain bangs inside the skull and is bruised. To reduce the incidence of concussion, it is common practice to wear a protective helmet. Protective helmets are ostensibly designed to deflect and absorb energy transmitted by impact to the helmet, thereby diminishing the risk of head and brain injury resulting from the impact.
Protective athletic helmets have been worn for almost a century, and have evolved from sewn leather, to helmets having molded plastic outer shells with suspension webbing or other head fitting structures such as foam pads, air bladders, or padded molding on their interior. Despite the evolution of the protective helmets, the reported rate of concussions has been increasing amongst student and professional athletes in many sports. While some experts have attributed this increase to better reporting and diagnosis, other experts have attributed the increase to increased forces generated as competitive athletes continue to increase in size (mass) and increase their ability to accelerate.
What has not been necessarily considered is that the increase in concussions actually may be attributable to the structure of the evolved protective helmets. In particular, the molded hard plastic helmets have not been shown to absorb energy effectively as they tend to transmit pressure waves, and in helmet to helmet contact situations may actually add to trauma. In addition, the evolved protective helmets have a considerable weight that may lead to other injuries.
It is also known that head trauma resulting in traumatic brain injury (TBI) has become a common occurrence in the military. A common cause of TBI is damage caused by explosive devices such as improvised explosive devices (IEDs).
TBI injuries fall into several categories that may have different symptoms. Mild TBI (MTBI), commonly referred to as a concussion, is a brief loss of consciousness or disorientation ranging up to thirty minutes. Although brain damage may not be visible on an MRI or CAT scan, common symptoms of MTBI include headache, confusion, lightheadedness, dizziness, blurred vision, ringing in the ears, fatigue or lethargy, behavioral or mood changes, and trouble with memory, concentration or attention. Severe traumatic brain injury is associated with loss of consciousness for over thirty minutes or amnesia. Symptoms of severe TBI include all those of MTBI as well as headaches that increase in severity or do not abate, repeated vomiting or nausea, convulsions or seizures, dilation of the eye pupils, slurred speech, weakness or numbness in the extremities, loss of coordination, and increased confusion or agitation. TBI injuries can cause lasting physical and cognitive damage.
Presently, the U.S. army utilizes the Advanced Combat Helmet (ACH) that incorporates ballistic fiber such as KEVLAR (a trademark of DuPont of Wilmington, Del.), TWARON (a trademark of Teijin Twaron, B.V. of the Netherlands), or ultra-high-molecular-weight polyethylene (UHMWPE). The ACH has a suspension system including a rear suspension system to which a ballistic “nape pad” is attached. The nape pad is intended to reduce soldier deaths from shrapnel wounds to the neck and lower head.
Despite the introduction of the ACH, TBI injuries continue to be a major cause of concern.